Technical Abstract:
Trials were conducted to examine the effect of commercial processing and refrigerated storage on Aeromonas bacteria in the native bacterial flora of broilers. The whole carcass rinse procedure was used to recover bacteria from prescalded, picked, prechilled, chilled, and refrigerated carcasses. Bacteria in carcass rinsates were then enumerated on Iron Agar. Isolates recovered from the rinsates were identified with the MIDI Sherlock Microbial Identification System, and dendrograms were prepared to determine the degree of relatedness between the Aeromonas isolates. Findings indicated that significantly more Aeromonas spp. and other hydrogen sulfide producing bacteria were recovered from picked broilers than from unpicked, prescalded broilers. Although, the number of these bacteria on prechilled and chilled carcasses was usually significantly lower than on picked broilers, the bacterial population increased during refrigerated storage. Dendrograms of Aeromonas isolates indicated that the same strain may be isolated from carcasses taken from different locations on the processing line, as well as from carcasses processed on different days at the same facility. Aeromonas species isolated from the carcasses included Aeromonas caviae, Aeromonas hydrophila, Aeromonas ichthiosmia, Aeromonas salmonicida masoucida, Aeromonas schubertii, and Aeromonas sobria. Data on the sites and level of carcass contamination by Aeromonas spp. indicated that the mechanical picker may be a source of carcass contamination by Aeromonas bacteria. The findings may be useful in designing intervention methods to reduce the spread of spoilage bacteria during processing and increase the shelf life of refrigerated fresh poultry.